Lost to Time
by itshannieee
Summary: Harry hated being an immortal. Absolutely hated it, the boredom and never ending loneliness until the day something piques his interest. A mystery with the thrill of excitement. The doctor promised himself he wouldn't be responsible of any more lives, yet how can he keep that promise? The loneliness of being the last time lord is a lot to bear. MoD!harry sort-of-slash DW/HP
1. Chapter 1

**Lost to time**

 **A Doctor Who & Harry Potter Crossover fanfiction**

 **MM Slash- but I'm not the best writer of explicitly so you've been warned. Doctor/Harry**

 **AN- imagine Harry Potter canon happened century's before.**

 **After lifetimes alone two lonely souls find each other, but what are two heroes to do when they both fear becoming involved.**

Chapter 1

Harry stood, staring intently as the last of his generation was covered in dirt. Reading the headstone Harry felt his heart ache; _'Luna Scamander, happily returned the earth that gave her light'._ Luna had been Harrys last link to life, his last true friend and the only person who had truly seen Harry for who he really was. Some had thought the airy blonde had been odd, _a weirdo_ , but Harry knew now that she was, perhaps, the sanest person in the world. She just happened to see things that others didn't.

"Come on, Uncle Harry," prompted Rose Malfoy: Ron and Hermione's daughter, who had married Scorpius, the only son of Draco Malfoy. Looking around Harry saw that they were the last ones still standing around the grave, in a graveyard filled with his friends and family buried long ago. Even little Rosie looked ready to join them, her once illuminous Weasley red hair faded into grey and her face aged with lines. Not that Harry looked any better, but his age was a lie, a simple glamour used to make it so he could say goodbye to the last of his friends without questions and trouble.

Underneath that glamour, however, Harry Potter still looked as young and fit as the day he had defeated Voldemort, nearly 200 years ago.

Harry had first noticed something was wrong when he had been in his early 20's. After the final battle, he had done what had been expected of him. This being, he had gotten married to the girl, settled down and had became an Auror. It was during a raid when he and Ron, his partner and lifelong best friend, were attacked by a few remaining Voldemort supporters, that Harry had noticed that he had changed.

The battle was nearly over when Ron had cried out, distracting Harry as he turned instinctively to his first friend. He had not noticed the spell heading his way. He only noticed it when it hit, when the pain spread throughout his body and his life force began to be ebbed away.

However, instead of Heaven or Hell or even Kings Cross he had once appeared at, Harry went– well, the best explanation was nowhere and everywhere at the same time. When he opened his eyes Harry was greeted with a vast emptiness before a voice caught his attention.

"So, master, you have finally graced me with your presence," a voice, void of any inflection said.

Spinning Harry tried to see where the voice was coming from, who it was speaking, but the nothingness remained and he saw nothing.

"I don't understand… I'm _dead_ ," Harry said, his voice shaking slightly on the last word. He thought of Ginny, who had recently began to talk about starting a family. They had waited to have their own children, Ginny not wanting to take the time off as she was just starting out as a professional quidditch player.

Besides her, he thought of his friends, of everybody who he loved.

"Yes, but to you, to _us_ , life and death are meaningless. You are my master and I am yours." The voice responded, and Harry finally realised it was coming from everywhere. The sound surrounded him in this empty place.

"So, I'm not dead?" Harry questioned, confused evident in his words.

"You shall never truly die as long as you are my master, Master," the voice told him from the nothingness.

Harry thought about this before he had a moment of clarity, an epiphany that had been delayed by his panic.

"You're Death, aren't you?" Harry asked cautiously. He was remembering the legend of the hallows and how the wand and stone had reappeared to him a week after the battle and kept doing so until he had finally had enough and placed them within his vault.

Suddenly the darkness lifted and Harry saw in front of him was Death. The image was how Harry had always depicted Death being; tall, almost formless, covered completely by a flowing black cloak and holding a scythe as tall as Harry himself.

"I am sometimes known as Death, but I have had many names thought the ages," Death explained.

Harry nodded absently, running his hand through his hair. He had grown it out recently in an attempt to tame it, an attempt which had worked quite well, although it would always have a wild look to it. The following silence Harry realised was deadening and Harry searched his mind for something else to say.

"So, the legend of the three hallows was true, and i'm the master of Death?" Harry asked, if only for clarification that this is what was really happening. Knowing his luck, it could just be another weird coincidence.

"Yes," Death said.

"But, couldn't I just give away the hallows and be free?" Harry asked, recognising that it was a fools hope but still wanting to know or sure.

Death remained silent for a few seconds before he replied with, "you are my master, my true master, and my master you shall always remain,"

"But… what about if somebody else was to claim all three? Surely I wouldn't be your master if that happened," Harry tried to reason, he didn't _want_ to die, but he didn't want to be this… _this thing!?_

"Perhaps, but that happening is not something I can foresee," Death told him.

Harry sighed and resisted the urge to punch the wall in his frustration. _Why couldn't he ever catch a break?!_

"So, what does this mean, truly? Being your master?" he asked, resigned to his fate.

"It means you are are master, and with that you are like I: unchanging, immortal, a constant in a world of progress." Death said.

"I noticed I still looked young a while ago… will I not age?" He asked. He knew that wizards aged at a slower rate than muggles, but Harry had started began realise not too long ago that while his classmates had started to mature he still held a certain boyish quality.

"Age is just another sign of decay and death," Death spoke, confirming Harrys fear. _Stuck at 17_ _…_ _great_.

"I see," Harry said, the implication of it finally hitting him. He would have to stand back and watch everybody he knew– everybody he loved grow old and die. His friends. The Weasleys. And, Merlin, even _Ginny_. Selfishly, he was relieved now that he hadn't had a chance to father a child with his young wife. He couldn't bear the thought of watching a child he sired grow old only to disappear from his life while he remained young.

"Will I meet you every time I… _die_?" Harry questioned.

"No," Death disagreed, "I shall see you when you need me but until then master, you are free."

Ironically Harry realised that he would never truly be free. He would never have the chance to gain that ultimate freedom. He was trapped, forever unchanging. Unable to re-join his friends and family in the next great adventure.

Realising this Harry closed his emerald green eyes to hide his pain.

"Harry!" The anguished voice of Ron drew Harry out of his pain, and slowly he sat up and looked around him. He was back in the abandoned warehouse he had been fighting the rouge wizards in.

Suddenly Harry was being crushed by an armful of crying redhead, "Merlin, Harry, you're alive! I thought– I thought you had d-died!" Ron wailed, pulling Harry closer, "I saw the spell hit, and I-" Ron cut himself off and hugged Harry closer.

Harry closed his eyes as he realised he as back and that he felt completely fine. In fact, he felt better than ever. "I'm okay Ron, I promise." Harry said, patting the tall redhead on the shoulder.

"How? I saw the spell hit! I saw you go down!" Ron exclaimed, finally drawing back.

Harry opened his mouth to answer but he found that the words were stuck in his throat. Eventually he sighed, before he made a vow to himself to talk to Ron, Hermione and Ginny together.

That conversation happened a week later. After the battle, Ron had insisted Harry go and see a healer. Said healer had cleared Harry immediately, citing he was in perfect health, much to Ron's relief and Harry's misery.

It had taken a week for Harry to work out how to tell the people that he loved the most about his new status. He feared for a moment their reactions but knew ultimately that it would be okay. Together they had taken down the ultimate evil. He had also invited Neville and Luna to the meeting, although he hadn't been as close to the duo in school the battle and re-building of their world had really brought them together.

"Harry, will you sit down and stop pacing!" an annoyed and 7 months pregnant Hermione demanded.

Harry sighed and turned to pace again. "I mean it mister, I may be pregnant but that doesn't mean I won't hex you!" the bushy haired witch threatened, brandishing her wand and pointing it at him.

Harry turned then and sat down, chuckling as Ron quickly fell into his role of doting husband and tried to calm the heavily pregnant witch.

"Why have you asked us here mate?" Neville asked, his voice richer than ever. Neville had aged _well,_ his blonde hair and skin touched from all the time he spent in the sun and among the greenhouses at Hogwarts, and was something Harry couldn't help but notice.

Looking at his friends Harry couldn't believe he hadn't noticed the subtle changes in all of them. Ron had filled out and lost the gangly quality he had during their teenage years, Hermione had a softer look to her, and even Ginny had matured, the lines of childhood ebbed away leaving graceful muscle. Luna looked the least changed but Harry could see some subtle aging.

It was Luna who answered Neville's question instead of Harry. "He has met the one constant in his life and is now changed," she murmured, the dreamy voice coming out soft.

Everybody turned to the white-haired girl and frowned whilst Harry gaped, "I– Luna… how?" the emerald eyed, now-immortal wizard asked.

Luna sent Harry a dreamy smile. "The nargles of course," she stated, like the answer was obvious and, perhaps, Harry realised, it was.

Ginny however had had enough, she had been worried all week about her husband, especially after Ron told her about the incident at the warehouse. She could feel Harry pulling away and closing off. He had barley looked at her all week, let alone touched her. "What does she mean Harry, what constant?" she asked suspicious, but there was a hint of desperation in her voice Harry couldn't help but hear.

Harry pulled his shocked eyes away from Luna and turned to face Ginny. He really did love her but now he couldn't see a future with her in it– at least, not with him as her husband.

"I have to tell you something, tell you _all_ something," Harry began, his voice soft as he looked into the faces of his friends and family. Luna was the only one who didn't look scared, she instead looked both excited and sad.

After that conversation life was never the same for Harry. His marriage to Ginny ended within a year, despite the redhead initially arguing that it wouldn't matter that Harry didn't age. But Harry had eventually sat her down and asked her 'if it was her, could she bear the thought of watching her children grow up and die?' Eventually Ginny had agreed and they separated, Harry giving her as much as she would take, which was not a lot.

After that Harry had not felt as welcomed by the Weasley's. Even Ron and Hermione, who understood the reasons behind the separation, seemed to pull away. He was still invited around, of course, as he was still an uncle to all the children, but he was also an outsider, especially after Ginny re-married 3 years after their split. Her new husband was a German pureblood whom she met during the Quidditch World Cup where England played. His name was Maximillian Ulrich, a nice enough wizard who Harry found quite pleasant.

Eventually life moved forward and Harry remained. He had lost something in that conversation with death: his passion, his spirit, his drive. After his separation, Harry had moved back into Grimmauld place with Kreacher, the old elf happy to serve Harry. He had retired from the aurors, closing himself off from the world. He had maintained some contact with his friends but seeing them only brought Harry bittersweet happiness.

It was Luna who had eventually pulled Harry back into the world with unwavering support and acceptance. She had practically forced herself into his home one day and refused to leave unless Harry came with her. It had been her who forced Harry to accept his status and embrace his new existence. Her who asked Harry what he wanted to do with his unending time, her who brought books on magic, on cultures, on languages. It was all Luna, who had forced Harry the unchanging to change, to adapt and learn more about the world.

Now Luna with gone. And so was all of the Weasley's, Neville– hell, even Draco was gone. Harry was officially alone. He was 213-years-old, yet he looked 17. He was lost in the world, adrift.

The first-time Harry ever considered life outside of earth was when he was 221. He had taken to spending his time in the muggle world, having allowed himself to ' _die'_ with the help of the goblins shortly after Luna's passing. Said goblins were the only ones left who knew of his immortal status. His name was still a legend to his people, even with him becoming a recluse his story was told: the whispered hero, forever spoken about by the masses.

Harry, however, had moved on, going by Callen James Black. Callen after his mother Lily, James… well that was obvious and Black after Sirius. He had been shopping in London, trying to find clothes that fit his forever teenage body.

The turn of the century had once again brought about a change in clothing and Harry had decided that he would fit in, despite not having any plans on actually socialising with people wearing clothes that didn't make him stand out would help with when he needed to. He didn't want friends– friends just meant more people he would eventually lose.

Harry had been going about his business like usual when the screaming happened. It had only been his centuries of practice that didn't have him panicking. Instead he called on his magic and made himself invisible, charming it so that even his scent was covered.

Scanning the crowd Harry couldn't believe it. The mannequins, they were _walking_? They were also attacking people. With a sigh Harry flicked his wrist, he did _not_ want to be dealing with this, but the containment squad attached to the ministry appeared to be running late and he couldn't just sit back at watch as the helpless muggles _died_ in an unprovoked magical attack. It had been decades since such an obvious attack had happened and Harry had to wonder if there was a new Dark Lord rising.

With the ease of countless years of mastery Harry went about trying to de-spell the mannequins and allowed himself to gape when he realised they were not spelled. They were plastic– _living_ plastic. What had the muggles been up to?

Harry thought back to every book he had read, every story he had heard and drew up a blank. What he was seeing and when he knew to be real were not complying. In his long life, Harry had allowed himself to become a bit of a fanatic, reading and storing all the information he could on anything he wanted– which turned into a little bit of everything. Ron had once joked in one of the rare moments he had visited Harry, that Harry had turned into Hermione, only worse.

Seeing as he couldn't de-spell the mannequins Harry instead started to blast them, making sure that he went unnoticed and had stunned the muggles first. He didn't want to be found out by the ministry for revealing magic after having so successfully disappeared for years.

It was as the last mannequin turned trying to locate him that Harry felt it. A surge, not magical but it was _something_ _–_ then the last mannequin jerked, suddenly fighting for control before it fell to the ground. Scanning it quickly Harry found it was now just plastic, no trace of life, no residual magic, not even that strange energy from before. It was _just_ plastic.

Looking around at the carnage Harry vowed to himself he would find answers before he apparated away. However, not before he heard a strange sound, a whirring of engines, and a girl's voice shouting the word 'Doctor'.

Returning home Harry was surprised when he felt a flicker of interest build up. It had been so long since anything had caught his attention, and _this_ , this right here was a mystery he would love to solve.

The Doctor stood, looking at the young girl he had brought along with him. He had vowed to himself he wouldn't do this again. He wouldn't endanger anybody else, he wouldn't be responsible for somebody's life and their subsequent death, but… this girl she had such potential. He could practically see it, her life and its possibilities and it was _amazing_ , magnificent even.

However, there was something else, just as he had closed the door. He had felt it, a shift, even the TADRIS had noticed it. However, when he had asked the ship, she had seemingly not registered it, asking again resulted in what the Doctor could only summarise as smug laughing from the sentient machine. Shocked, he pulled out his sonic and was about to try and get some answers when he was interrupted.

"So, where are we going then? Past, future, a new world or even an old world?" Rose asked pulling the Doctor away from his mental conversation with the TARDIS and back into the present.

The Doctor thought for a moment before he grinned. "How about the end of a world?" he asked.

Rose laughed, "bring it on space man," she said, her blue eyes sparkling with the thought of adventure.

The end of the world had been both frightfully overwhelming and dreadfully underwhelming for Rose. She was in the year 5,000,000,000 standing on the observation deck of space station Platform One and she felt so small. The whole world was gone yet she had just spoken to her mum on the phone. The planets destruction had not even been observed, the mess with Cassandra the human trampoline had caused the planets final seconds to go unnoticed.

"It's gone," she whispered sadly to herself, watching as the debris shot harmlessly by the station. The adrenaline from almost dying as well as the shock of seeing the Doctor allow Cassandra to die was catching up on her and she felt like crying and laughing all at once.

"It's gone and yet it's still there," the Doctor told her, stepping out from behind the door. He had allowed Rose a moment while he himself collected his thoughts. Jabe had died, and, although he had just met her it was another death he had caused, another to add to his list. Even Rose had almost died, making him wonder if he was doing the right thing.

"My mum's down there, nothing but ash," Rose whispered, whether to herself or him the Doctor was unsure.

The Doctor laughed, "now that's morbid," he said, "you should know that your mum's fine, you just spoke to her. That down there, that won't happen to her. To her the world is safe and fine. You see, time… times just this thing, this big, wibbly, wobbly thing. Everything that's ever happened and everything that will ever happen is all going on right now," the Doctor explained.

"But– but" Rose stuttered, her exhaustion and shock making it hard for her to come to terms with the idea.

The Doctor sighed before an idea hit him. "Come on, come with me," he said, and he grabbed Rose's hand.

Following after the mad alien Rose once again questioned what she knew about him– why she had followed him. Entering the TARDIS, she stood and watched as he ran around manically pressing buttons and pulling levers. Eventually the ship settled and the Doctor turned to face her with a smile. "Come on then," he said, his northern accent dispelling some of Rose's concerns. He was alien… but he also was not.

"Where are we now?" she asked as he opened the door.

"Take a look," the Doctor said, indicating to the doors.

Walking outside Rose looked around. "This, this is London. We're in London," Rose said, recognising the street.

"London, England, Earth year 2005. Only a few hours after we left to be precise." The Doctor told her.

Looking around in wonder Rose span in the circle, "It's all still here!" she exclaimed.

"All still here," the Doctor confirmed.

"They have no idea," Rose said, looking at the crowds that where ignoring them as they went about their business.

"Nope, life for them is on-going," the Doctor said.

"It's all still here, it will still be here for another 5,000,0000,000 years," she said excitedly.

"Yup, so where to now?" He asked her.

"I don't know, I don't know what I want. Wait, actually, can you smell that?" Rose changed what she was saying halfway, distacted.

The Doctor sniffed, his nose so much more powerful. He could smell the sweat of the people, the pollen in the air, hell he could tell the time in the century by the smell of the pollution, but he could also smell– "chips, I can smell chips."

"That's what I want, I want chips," Rose decided.

"Then chips it is," the Doctor agreed.

"Come on then, your treat." Rose told him, looping her arm through his and giving him a tug.

"I don't have any money." The Doctor admitted happily.

Rose laughed, and sighed dramatically, "rubbish date you," she said, "I suppose chips are on me then."

"I can't believe that was Charles Dickens. _The_ Charles Dickens!" Rose exclaimed, exiting the TARDIS in what she believed to be her original time.

"Yup, good ol'charlie boy," the Doctor agreed.

"So, this is just a few hours after we left," Rose asked him, amazed.

"Yup, you left last night, about 12 hours ago," the Doctor confirmed.

"Great, I just want to say a quick hello to my mum then we can be off," Rose said, turning and walking towards the flat block, "don't you be going off anywhere without me

The Doctor hummed his consent and turned, looking around. His eyes spotted a newspaper and a missing persons ad. Seeing the face in the ad his eyes were drawn to the date. Realising his mistake, he ran after the human, but he didn't make it in time.

"12 months, and not a word. Not one phone call!" He heard Rose's mum shouting as he approached her door.

Appearing the Doctor sent Rose a sorry look, "it's not been 12 hours, its 12 months. You've been gone a whole year. Sorry." He said, smiling brightly before he quickly hid his expression.

Rose sent the Doctor a hard look as she tried to calm her now sobbing mother. "I gathered," she replied dryly, just as her mother started to lay into both of them.

Harry ran his hand through his hair and sighed, he had found zero reliable information on this so called 'Doctor' in the magical world and was actually considering 'offing' himself just so he could question Death. He had searched the Black library, and even donned a disguise and entered Hogwarts. The old castles wards had welcomed him like a long-lost son and helped him in hiding his presence. He had spent almost four months practically living in the dusty stacks before he gave up.

Eventually realising that the magic world wouldn't hold any answers and he decided to 'go muggle'. Harry had worked hard to infiltrate the muggle world and could pass as a muggle easily. This was contributed to his more Slytherin traits having been developed over the years.

He could now easily slip between the worlds and go unnoticed. He had even been able to work on his magic, making it possible for him to allow magic alongside muggle technology. When technology had started to advance the wizarding world had fallen behind and many had given up working with technology as their magic worked negatively with it, instead separating further from their muggle counterparts. The gap between the two societies had become a lot bigger. Harry though, he had embraced the situation. It was a mystery that took him nearly a decade to master but now here he was, a wizard capable of utilising both magic and technology. It had been a task which Harry had enjoyed as it took up his time, something of which he had infinite amount of.

His search had rendered one conclusion though, which was that whoever the Doctor was, he most definitely wasn't a wizard.

Harry took this thought and planned, apperating silently to The British Library to go through their archives. Here, what Harry found shocked him. There were mentions of the Doctor throughout history, men popping up all over the place, making Harry assume the title was either passed down or transferred. Harry found mentions of events in history, conspiracies and theories that all surrounded this 'Doctor'. Things like wherever he went disaster followed, yet there where also mentions of him during inconsequential times, and times of celebration making Harry wonder… just who was this man?

The rabbit hole he found himself in was the first thing in a very long time that had Harry feeling excited. With age he had grown apathetic. He had become bored with the world and now he had an honest to god _mystery_.

Research lead Harry down more dark and mysterious paths, until he eventually found himself a year later sitting with a laptop. His magic decrypting the national defences secret archives. This use for his magic had been a startling discovery but one of the most useful ones he had to that day.

The files were both old and new and so intriguing Harry could barely stop the smile he had from forming. Aliens. Honest to god _aliens_ from outer space. They were real and, apparently, the muggle government knew all about them– this made Harry wonder if the magicals had any idea but he guessed they didn't as they had separated themselves from the muggle world so completely in the last century.

Withdrawing his magic Harry allowed the decryption to stop and briefly read through the files he had found. This man– well, alien, made Harry look practically selfish. He took being the selfless hero to the next level. Always fighting to save the world and never expecting anything in return, a true martyr. Not finding anything new in the files Harry briefly felt his excitement fade away. He had answered the great mystery and done what he had set out to do. And, honestly, he didn't know what to do, or turn to, now.

Sipping on his latte Harry closed his eyes and sat back to enjoy the mid-morning sun. The Embankment café he was sitting at really did serve the best coffee in London. He should know, he had become addicted to the drink in the 70's and had literally been everywhere to find the best cup. Soon Harry found himself slipping into a light meditation, a practice he had developed just after his 80th birthday as a way to maintain constant occlumency shields.

However, his relaxation soon disappeared as screams and shouts soon drew Harry out of his mind and back into the present. Looking up Harry felt his eyes widen as he saw a flying saucer crash into the buildings of parliament and take out some of Big Ben.

Well, at least his life wouldn't become boring to quickly, he mused as he stood. Placing 10 pounds on the table, he apperated to the crash site.

Harry stood and watched as a body was pulled from the wreckage in the Thames. He couldn't believe alien contact had been made. Making sure to keep a repellent charm up as well as a silencing spell, Harry made his way towards an official looking tent and listened in on the muggles conversation. The repellent charm would work like an anti-muggle ward but was easier to maintain on a person Harry had discovered.

 _"'M_ _issing_ _–_ _been gone all day!" a man in a suit_ _exclaimed_ _, his appearance_ _disheveled_ _and he was clearly stressed_ _._

 _"T_ _hen who's in charge?"_

" _Green," somebody else_ _responded_ _, this time it was a woman dressed in military clothing. She looked quite important._

" _G_ _reen, as in the Sugar man? He's hardly the best option,"_

 _"H_ _e's the highest authority_ _we have_ _until the cabinet is recalled_ _._ _"_

Hearing this Harry wondered about the chances of such an event happening when all of the government higherups happened to be gone and put the chances at around zero. Having his interest once again spiked Harry listened in, listening to them the speak about the hospital the alien was going to. Deciding that he would continue to investigate, the most interesting thing to happen to him since his teenage years, Harry once again apparated, this time near the hospital he knew the alien was heading to.

Walking in Harry watched as the military set up a perimeter and investigated their equipment. Harry had never really seen any muggle weapons and upon inspecting them he decided he didn't like them. After all the death he had seen in his long life, Harry abhorred weapons, which had the sole purpose of harming others. Turning away from the soldiers Harry entered a smaller room, something that looked like a large cupboard. Just as he was about to turn back however his interest was piqued. There was a familiar whirling sound of engines.

Hearing the commotion Harry turned just in time to have somebody collide forcefully into him, the shock sending them both to the floor. Hitting the floor with a daze the Doctor looked down into the greenest eyes he had ever seen and was confused.

 _"W_ _ho are you?"_ he questioned, looking at the man who had suddenly appeared and unsure if he had just been invisible or if he had only just noticed him.

 _"H_ _ow did you run into me?"_ Harry asked simultaneously. The shock of somebody hitting him while he was maintaining his repellent ward had been enough to make him drop his invisibility spell.

"I'm the Doctor," the Doctor said, grinning at the man he was still lying on top of.

Harry stared up at the man and traced his features with his eyes. He looked to be in his 40,'s, buzzed dark hair and brown eyes. His ears also happened to be rather prominent. "The Doctor?" Harry questioned, not believing his luck.

The Doctor however didn't know about this and instead stood and offered Harry his hand. "That's me, now, who are you?" he asked, staring at the man– or more presicely teen guessing his age to be around 18. The man-boy had black hair that fell to his shoulders in mad waves, pale skin and the greenest eyes the Doctor could recall seeing in a human, there was also an unusual scar on his forehead that the Doctor felt like he should recognize. The boy was also skinny but looked healthy in his form fitting black jumper and dark jeans. The teen was quite handsome, and held an allure of power that the Doctor found strange. " _W_ _hat_ are you?" he added as an afterthought.

Harry held back his answer as he studied the man who was studying him, hearing the question Harry held out his hand and gave the name he had been going by for the last few years, "Callan James Black," he told him, "and I'm guessing you don't mean a Leo? I'm human."

The Doctor smiled and shook his hand, intrigued. "Pleasure Mr Black. Now, what's a boy like you doing in a place like this?" He asked, curious. This place was on lockdown, how a supposedly human teen had gotten passed all the locked doors made him curious.

Harry looked around and saw they were still in the cupboard "What, can't a man casually hang around in a cupboard waiting for unsuspecting men to suddenly fall on them?" he asked, enjoying the banter. It had been so long since he had somebody to talk to, let alone flirt with.

"Well they could, but I know this place is locked up tighter than Fort Knox, so tell me Callan, why are you here?" the Doctor asked.

"Why? This is the most interesting thing to happen in a long time," Harry replied honestly.

The Doctor let out a laugh, "interesting, I though you apes hated the unknown?"

"I would like to think I'm more than the average ape," Harry responded.

"Well then Mr Black, would you fancy joining me on an adventure?" the Doctor offered without thought. He already had Rose as a companion but for some reason he felt drawn to this dark-haired boy.

Harry considered before he smiled. What's the worst that could happen? However, seeing where the Doctors hand was about to go Harry regretted these thoughts.

"No don't-" However Harry's warning came to late and the Doctor opened the door that lead to the room full of soldiers and their weapons. Weapons that were immediately pointed at the two men.

"- _open the door,_ " Harry finished his sentence in a whispered shout, sending the Doctor a look of exasperation.

The Doctor shot Harry a smile before he turned and grinned at the soldiers. "Hello," he greeted jovially. Silly humans with their silly guns.

However, before the soldiers could even flinch, a woman's scream echoed through the room. Grabbing Harry's hand the Doctor ran towards the soldiers and started barking commands, something that startled them into action.

"Follow me," he said to Harry.

Harry ran after the alien and considered if he really wanted this much of an adventure. Sure, it was exciting and interesting, but he was old. He was tired. The flirting had been fun, the mystery intriguing but now he was living it. He didn't know if he wanted that. He had already lived and lost so much.


	2. Chapter 2

**Lost to time**

 **A Doctor Who & Harry Potter Crossover fanfiction**

 **MM Slash- but I'm not the best writer of explicitly so you've been warned. Doctor/Harry**

 **AN- imagine Harry Potter canon happened century's before.**

 **Also the last chapter has been heavily edited so check it out**

 **After lifetimes alone two lonely souls find each other, but what are two heroes to do when they both fear becoming involved.**

Chapter 2

 **Previously**

 _However, before the soldiers could flinch a woman's scream went out throughout the room, grabbing Harrys hand the doctor ran into the soldiers and started barking commands. Startling them into action._

"F _ollow me," he said to Harry._

 _Harry ran after the alien and considered if he really wanted this much of an adventure, sure it was exciting and interesting but he was old. He was tired. The flirting had been fun, the mystery intriguing but now he was living it, he didn't know if he wanted that. He had already lived and lost so much._

Entering the lab, Harry looked around and noticed a small Japanese woman cowering in the corner. Seeing as the doctor was more concerned with whatever was hiding, Harry approached her.

"Sssh, it's okay. The Doctor is here," he said trying to sound reassuring.

"I thought it was dead," she muttered almost hysterically.

"What is it?" Harry asked.

"It's- its" the woman stuttered.

"It's beautiful," came the Doctors voice. And it was, he had never before seen something like this, and for him that was saying something.

Harry resisted rolling his eyes, "that's great, truly, but it doesn't tell me much," he muttered.

Seeing the soldier that had come in with them tighten his hand on his gun Harry sent him a dark look. Alien or not, beautiful or not, he didn't want it killed unless it was a threat.

"None of that," came the Doctors voice, as he to noticed the soldier. "It's just scared." He chastised.

The alien, who Harry had just seen from the corner of his eye, was admittedly fascinating. Harry who had fought dragons, ridden Hippogriff's and Thestrals, swam with mermaids and almost kissed dementors found it both enthralling and to be honest disturbing.

Harry noted how the Doctor instantly took control of the situation, how the soldier who had previously been pointing his gun at them was new listening and following his orders.

"I thought it was dead," the Japanese scientist repeated to Harry.

Seeing how she wouldn't be telling him much, Harry slowly handed her over to the soldier and approached the Doctor, moving into a crouch next to him on the floor.

Looking around Harry spotted the shadow of the alien and felt his eyes widen when he got a better look at it, turning he nudged the doctor and lent in to whisper.

"Doctor that looks like-" Harry started, starring at the creature in front of him with fascination. It wasn't often in life that Harry saw the new things and this was definitely new.

"I know, it's brilliant," the Doctor said cutting Harry off before smiling widely.

"Hello there," the Doctor called out, hoping to calm the alien.

However this seemed to do the opposite as suddenly the alien let out a squeal and darted out of the room.

Harry jumped up just as the Doctor did and followed him out.

The Doctor wasn't sure what was in front of him, in all of his centuries he had never seen anything like this. Hearing Callan following, the Doctors grin widened, he liked this one.

However entering the hall his grin dropped, "Don't shot!-" he shouted, but before his words fully left his mouth a shot rang out.

Harry threw a shield up hearing the Doctors words but unfortunately he had only covered himself and the Doctor.

The Doctor sent the soldiers dark looks, "What did you do that for?" He shouted

Harry, who's eyes were trapped on the now dead body of the alien looked up then with fire in his eyes. "It was scared. It was scared and you killed it," he said, in a dark voice, not shouting.

The Doctor turned then and looked at the young man beside him, surprised at the about of emotion in his voice. Seeing his emerald eyes blazing he felt something in his chest loosen.

Back in the lab Harry watched as the Doctor and the scientist worked together, discussing what the alien was and all the discoveries the scientist had found.

Hearing them talk Harry felt his interest pique, he could only understand half of what they were saying but if he was right then it wasn't an alien but an ordinary pig- A pig with alien tech in its head.

"Why would aliens fake an alien crash?" He mused out loud.

The Doctor spun to look at the young man who was leaning against a nearby table, shocked he had been able to follow the conversation. _Not just a pretty ape but a smart one too._

"Why indeed," the Doctor said, walking up to the teen and offering him a hand. He had found out want he needed for now. Now he just had to go pick up Rose so they could investigate, maybe Callan would come too...

Harry looked at the mischievous glint in the Doctors eyes and was reminded of Dumbledore, his mentor and guide who had died such a long time ago.

The Doctor watched as Callan seemed to get lost in his mind for a moment, his emerald eyes clouding over with shadows of the past.

"Come on bright eyes," the Doctor said, tugging Harry's hand and pulling him out from his memories. He recognized that look, it was the same one he saw in the mirror and that shocked him. What had this seemingly young man been through to make him have such shaded eyes?

Letting himself be pulled, Harry wasn't surprised when they re-entered the cupboard the Doctor had crashed into him in. However, he was surprised to see a 1950's police box. He hadn't seen one in years.

Still being pulled along Harry watched at the Doctor opened the door and disappeared into the box. Shrugging his shoulders, Harry followed, he had seen many things in his long life that where different from what they seemed.

Once inside Harry let his eyes wander. This was a spaceship, a genuine alien spaceship.

The Doctor watched as the young man took everything in, his eyes flitting around. However never did they gain that look of incredibly, it was almost like he had been expecting this - _Just who was this boy?_

"Nice," Harry eventually said. Letting his eyes fall on to the Doctor who was standing and staring at him.

"You don't seem shocked, usually people are shocked when they come into the TARDIS," the Doctor said.

"TARDIS?" Harry queried, wondering what it stood for.

"Time and relative dimension in space- My ship," the doctor said, confused as to the non-reaction

Harry nodded, "I see, it's awesome," he said honestly. So the files he had hacked where right, the Doctor was a time traveller.

"Why are you not acting all human and shocked? This should blow your little monkey mind," the Doctor said

"Like I said earlier, I'm not your average person- or to be precise I said not your average ape." Harry said mischievous. Had he been a muggle or even younger he knew he would have been left gaping at such a sight, but at his age he had seen many things similar. Never a spaceship granted, but things binger on the inside- old news. Although thinking about it, Harry did wonder how it was possible, he guessed the Doctor wasn't using Wizarding space which gave the same effect.

The Doctor tilted his head, and mentally asked the TARDIS to scan the young man. He had never met a 21st century human who wasn't blown away by the TARDIS and its use of extra-dimensional space. Even other aliens and more advanced humans where usually taken back.

While waiting for the TARDIS to scan the mysterious youth, the Doctor asked, "Alien?"

Harry watched as the Doctor tried to work out what he was, before he felt a slight tingling go over and through his body.

"No. What was that?" Harry asked distracted, the sensation was foreign and if not for how in tune he was with his magic he would have missed it. It felt like somebody trying to use a soft form of Legilimency.

The Doctor was honestly shocked, nobody, well, nearly nobody, ever felt the TARDIS when she scanned them.

"What are you?" He asked coming close and circling Harry, staring intently. He even reached for his sonic to scan him.

"I'm a wizard," Harry said, he was pretty sure the statute of secrecy didn't cover aliens. Then he added, "A human wizard," just to be on the safe side.

The Doctor felt his eyes widen, wizard? There where wizards? How didn't he know this?

"What?" The Doctor asked incredulous. Lifting his sonic he watched as Callan raised an eyebrow, still the reading did say human.

"Yup, a wand waving wizard." Harry said, flicking his wrist for good measure so his wand appeared from his hidden holster.

"How come I've never met a wizard before?" The Doctor asked, staring at the piece of wood in Harry's hands. His own hands were itching to take the branch and run it through every scanner he owned, which were pretty much all of them.

Harry shrugged, flicking his wrist so the elder wand disappeared again. "The magical society is pretty isolated, they've pretty much cut off all contact with the muggle - sorry non magical- world."

The Doctor nodded, "I see," he says still shocked.

"There's also laws stopping people from revealing that society, people can go to Azkaban - magical prison, nasty place -if they reveal our society, so people hide when it in the muggle world. There was also an awful war around 200 years ago that decimated a lot of the magical population, since then they've become even more insular." Harry continued to explain, fighting not to be drawn into his memories of the war. They had lost so much, and for what? 200 years later their society was still as flawed and prejudiced as ever, sure muggleborns had more rights but the purebloods still ruled.

The Doctor nodded, so he could have met a witch or wizard then and just not realised. "Wait, why are you not worried?"

Harry shrugged, banishing his dark thoughts, "I figured that if you were letting me into your space ship then I should at least be honest, also I'm not worried about the ministry- magical government- I live in the muggle world. As long as you don't announce it to the world then I'll be fine."

The Doctor nodded, his thoughts running at a mile a minute. "So magic" he eventually said, focusing on what was bothering him the most.

Harry grinned, wiggling his fingers in front of him, "Magic," he confirmed.

The Doctor circled him again, "But- but- _how_?" he asked. Magic didn't make sense; it was just science that wasn't yet understood. How did this human, well all the humans who were apparently magical, come by these powers? It wasn't logical and the Doctor hated that.

Harry sighed, "I personally think it was a genetic code introduced by an outside source a few millennia ago as its hereditary, passed on through families with the occasional 'muggle born' popping up- Probably the gene activating in two carriers," Harry said, before he started to talk about how magic worked, wands, spells, wandless, potions ect.

The Doctor nodded and hummed, "What are the limits to this ' _magic'_?" he asked after Harry had given him the basics.

Harry jumped onto the side and started to swing his legs as he went through the laws of magic as he knew them, he had studied them over the years and tested their limits so he was pretty confident. He spoke of how spells worked and the development of wandless and wordless magic, even magical creatures.

"Your life span?" the Doctor asked, taking in all of this information. These 'magical' humans sounded almost like Carrionites or perhaps Eternals, however the Doctor was sure they were a mixed-breed of human-alien. Whilst the magical creatures he guessed where life forms from different worlds, hidden from the 'muggles' by the magical world.

"Around 200 years on average." Harry said, forgoing mentioning his own predicament. He didn't want to go into detail about The Hallows and his own immortality just yet.

"Mmmm, I see." The Doctor said, his theory about Carrionite-human crosses sounding stronger by the minute. Eternals lived much longer and even mixed with human blood they would surely live around 800 to 1000 years... however their banished cousins, their lifespan was shorter.

Seeing the Doctors face Harry lent forward not realising how close they were to each other, "So what was this outside source? I can practically see the answer on your face. You have a theory," Harry said, interested in the Doctors thoughts, he knew the man was an alien, and from what he had learnt from the hacked files he travelled through time.

"Carrionites, a cousin of the Eternals banished from their realm at the start of this universe for mixing their powers." The Doctor said.

Harry smirked, "Well they certainly mixed their powers with humans if they breed an entire race,"

The Doctor smiled, most apes would be freaking out by now knowing that they had alien blood, but Callan he just looked satisfied that his theory was right.

"So, aliens faking alien. What the deal with that?" Harry said, drawing the Doctor back to why they were in the TARDIS

The Doctor grinned, "I don't know," he said.

Harry shook his head, "If it is aliens, then what do they get from putting the world on red alert. I mean everybody going to be looking for them now..." Harry mused.

"Now that is the question," the Doctor said grinning, "let's go, I need to pick somebody up before we go adventuring."

"Somebody?" Harry asked standing back as the Doctor suddenly jumped into action, running around his ship and hitting random buttons.

"Rose, Rose Tyler. You'll like her she's brilliant."

Harry smiled at the mad aliens' obvious joy but he could feel it didn't reach his eyes. Rose was a human, wasn't she? He envied the Doctors ability to still be able to bond with people, Harry knew he held people at a distance, but he was just too tired of getting hurt ad seeing the people he loved growing old, of ding and leaving him behind never changing.

The Doctor frowned when he saw the bitter sweet smile on Callan's face. Such an odd expression for somebody so seemingly young.

"She's your… _companion_?" Harry said the word, remembering it from the files he had hacked- The Doctor and his companions.

The Doctor hummed, "Yes, I suppose she is," he said smiling widely. He still felt conflicted but Rose was a smart girl... or… well she was certainly creative.

"So magic man, how do you feel about joining us?"

Harry smirked, "I'm game, but call me that again and I will see if magic works on you Time Lord,"

The Doctor seemed to still before continuing to fiddle with the ships controls, "How do you know I'm a time lord?" he asked

Harry tilted his head to the side, "Oh, I forgot to mention. I looked you up, I saw you last year after the Christmas mannequin fiasco and did some research. You are a hard man to pinpoint but I eventually _stumbled_ upon some files,"

The Doctor snorted at the innocent way Callan spoke, "So you can use your magic to hack things? I thought you said magic and technology didn't really work together,"

"They don't for normal people, but like I said, I'm not normal,"

The Doctor hummed, he wanted to continue to ask questions, to pick and prod until he was satisfied but he could see the shadows building in Callan's eyes and knew to stop. "You might want to brace yourself," the Doctor suddenly said just as the TARDIS lurched violently.

Harry barely had a second to react before he was thrown forward, landing in a pile of awkward limbs on top of a shocked looking Doctor. Harry could feel a blush threatening to take over him but instead thought to look unbothered.

"Hello," he said calmly, while inside he was burning, it was a rather intimate position.

The Doctor sucked in a breath as the wizard looked down on him, black hair falling around the pale face and making those strange bright green eyes seem to glow. "Hello," he said.

Harry chuckled and stood up, wincing slightly as he felt his back crack. He may be immortal but it still took a little time for injuries to heal.

"So, where are we?" Harry asked

"still in London, Rose lives here with her mum."

Harry nodded and followed the doctor out. Looking around he saw the estate was one of the ones put up in the last half century by the council, he hadn't been in one before but found it wasn't to his taste, he had nothing against the people who live in places like this but the idea of being so closely packed together made his skin itch. Humming he also noticed the missing posters.

"Charming," he said, noticing the graffiti on some of them.

The doctor snorted, "We can't all be a highborn little lord now,"

Harry allowed an eyebrow to rise, "Highborn?"

"You have this air about you," the Doctor summarised

Harry hummed again, "I see, well you're not wrong although I no longer have use of my titles." He had passed them on when he 'died' in the wizarding world, passing the black lordship onto Rose and Scorpius's second son, the first having gotten the Malfoy lordship. While the Potter lordship went to Teddy and Victories daughter, their son having gotten the Weasley lordship.

Before the Doctor could pry more from the intriguing creature in front of him Rose suddenly appeared, with Mickey trailing closely behind her. "Doctor," she called running to him.

The Doctor grinned, "Rose Tyler, Mickey boy"

Rose suddenly stopped a few feet from him, and the Doctor saw her eyes narrow.

"Who's this?" she said, looking Harry up and down with suspicion. They looked around the same age, but this boy stood so confidently next to the doctor and rose could recognise the quality of his clothes from when she had worked in the designer section of Henriks.

Harry watched the blonde check him out with curiosity, "My name's Harry," he said, nodding to them both.

"Oh," Rose said, she didn't know why but even his voice annoyed her, it was so smooth. "but, who is he?" she said to the Doctor, not noticing how demanding her tone was

"He's a friend," the Doctor said, staring at Harry who rose an eyebrow in challenge to the title of friend, "He'll be joining us,"

Harry snorted softly, "For now," he said, not sure he really wanted to join them permanently.

Rose started incredulously, who would _ever_ give up the opportunity to travel with the Doctor?

"We need to go," Rose said suddenly remembering what her mum was doing. When she had seen the police box materialise, she had run off, saying she was going to call the army or the government.

"You can't Rose! You can't just leave us all again! You don't understand, they thought I had killed you, thought you were dead!"

"Why?" the Doctor said, before adding quickly, "Why do we need to go?"

"My mum-"

Harry watched this all with interest before suddenly the squeal of tire was heard and a helicopter appeared.

"I do believe this may be the reason," Harry said softly, taking a step back when the black clad soldiers got out and pointed their guns at them.

The Doctor snorted at the wizard, "None of that lip now you,"

Harry blinked innocently, "But I thought you like my lips, I'm sure I've caught you staring at them at least once,"

Mickey who was watching them snorted before he realised they were being surrounded. Looking around he quickly sent them all a cheeky grin and ran away, narrowly missing the soldiers.

The Doctor grinned at the wizard and exaggeratedly wigged his eyebrows in response, ignoring mickey as he made his escape.

Rose was watching this with annoyance but didn't respond, "Doctor what are we going to do?" she asked

"We surrender," the Doctor said loudly. "Take us to your leader," he added as an afterthought.

Just the Jackie appeared, "That's him, that's the Doctor," she shouted, barging through the soldier's ad pointing at the alien who she though had stolen her daughter from her.

The soldiers however ignored her, "You will come with us," the designated leader said.

"Of course," the Doctor said, bouncing on the balls of his feat in excitement

"You will all come with us," he repeated

"Yup," he said walking forward before suddenly turning and grabbing Harry, "Come along, can't keep number 10 waiting,"

Harry snorted again, "Of course," he mimicked.

Rose huffed and followed them.

"What are you doing? That's my daughter!" Jackie wailed, realising Rose was following the Doctor and soldiers.

"Ma'am please step aside," one of the soldiers said to the steadily growing hysterical woman.

"But- Rose stop it! You stop it right now!"

Harry stopped and looked at Rose, "You should talk to her," he said, "If not now then soon,"

"What's it to you?"

"She's your mother. You never know when something could happen. She clearly loves you and was worried,"

Harry said this thinking about all of the people he had lost in his long life, he would give anything too see them all again and tell them he loved them.

The Doctor watched them with fascination, "Come along you two, not time for family drama, aliens to investigate, mysteries to solve and all that,"

Harriet Jones wasn't a naive woman, nor was she easily lead astray however at that moment she prayed she was being played for a fool. Those creatures, aliens, _things_ where monsters, MP Joseph Green the newly named acting named acting Prime Minister was an alien apparently called a Slitheen.

Harriet repressed a frightened sob as she recalled how the man, creature, alien had forced its giant green body out of the shell that had been Green and dropped the skin suit to the floor. She didn't understand how or why this was happening but she wold be dammed if she stood back and let his and his two alien accomplices Margaret Blaine and Oliver Charles get away with destroying the Earth.


End file.
